Earth boring bit



Feb. 9, 1954. J, A MOORE l 2,668,691

EARTH BORING BIT Filed NOV. l5, 1951 INVENTOR. {a/ /Vaff l I Wil/7h27 Patented Feb. 9, 1954 UNITED TAT es eATsNT OFFICE EARTH BORING BIT `l'ohn Allen Moore, Denver, Colo.

Application November 15, 1951, Serial No. 256,545

(Cl. Z55-61) 2 Claims.

This invention relates to an earth boring bit, and is more particularly designed to be placed on the extremity of a length of pipe for boring a horizontal hole for the pipe from a water main in a street to a residence or other service connection.

The principal object of the invention is to provide a boring bit of this type which will be simpleand economical to manufacture; which will be highly eicient and self-cleaning in use; and which will eliminate clogging of. the water passages from foreign materials in the water supply.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and eiciency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. 1 is a side view of the improved earth boring bit;

Fig. 2 is a front end view thereof;

Fig. 3 is a longitudinal section through the bit, taken on the line 3 3, Fig. 2; and

Fig. 4 is a side view of the bit during a pre liminary step in its manufacture.

The improved bit is preferably manufactured from a short length of heavy wall steel tubing I0 having external pipe coupling threads II formed on its one extremity. A plurality, preff erably four, of uniformly spaced slots I2 are cut into the other extremity of the length of tubing Il to form uniformly separated, toothed fangs I 3. The leading edge of each fang is notched inwardly, as shown at I4, to form a relatively sharp, hook-like extremity on the fang. The trailing edge of each fang is arcuately curved, as shown at I5, to accentuate the sharpened extremity of the fang and to provide clearance therefor.

The formed fangs are then separated and spread outwardly and forwardly, as shown in Fig. 1, to form a flower-like, daring extremity, with the point of each fang uniformly separated from the points of the adjacent fangs, and with the points spaced outwardly from the surface of the tubing I0 a distance in excess of the exterior radius of the tubing. The fangs may, if desired, be heat-treated to increase their wearing qualities.

A tubular plug member I6 is mounted within the tubular portion of the tubing I9 in any desired manner, such as by means of screw threads, welding, soldering, shrinking, etc. As illustrated in Fig. 3 of the drawing, the plug member I6 is threaded into the tubular portion of the tubing I0.

A water jet tube I1 is xedly and coaxially mounted in the plug member I6 and extends completely through the latter, projecting rearwardly from the tubing I0. The rear extremity of the jet tube is reduced in diameter to provide a restricted water intake opening I8. The jet tube is also diametrically drilled to form side water ports I9 in that portion of the tube which projects from the plug member I6. The diameter of the ports is less than the internal diameter of the jet tube I1.

In use, the threads Il are screwed into a pipe coupling, and the pipe coupling is threaded onto one extremity of a length of water pipe. The other extremity of the length of pipe is provided with any of the usual rotating braces whereby the pipe may be rotated and forced forwardly while water under pressure is supplied therethrough.

The pipe is rotated in a clockwise direction to cause the sharp, hooked, toothed fangs I3 to cut a circular bore through the earth as the pipe is forced therethrough. The earth cuttings are 'washed rearwardly between the widely spaced, toothed fangs and discharge from the entrance of the bore, In addition to washing the earth rearwardly, the velocity of the water jet exiting from the jet tube is suiiicient tocut and wash away hard, packed earth ahead of the jet.

Sand and earth occasionally get into the bore pipe during the attachment of the hose thereto. These foreign materials, however, cannot clog the jet tube, since the restricted intake opening I8 and the restricted ports I9 prevent particles of suflicient diameter to clog the jet tube I1 from reaching the latter.

While a speciic form of the improvement has been described and illustrated herein, it is to be understood that the same may be varied, within the scope oi the the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

1. An earth boring bit comprising: a relatively short length of steel tubing; a plurality of relatively sharp fangs formed on one extremity of said tubing, said fangs extending outwardly and forwardly from said tubing to form a oWer-like, aring extremity thereon; a plug member xedly mounted within and extending substantially throughout the length of said tubing and closing the latter; a water jet tube coaxially mounted in said plug member, said jet tube being xedly supported by said plug member so as to project rigidly rearward of the latter; a reduced-diameter rear extremity on said jet tube; and means for coupling said tubing to a drilling member.

2. An earth Aboring bit as described in claim 1 having side Water ports formed in the rearwardl projecting portion of said jet tube.

JOHN ALLEN MOORE.-

References Cited in the le of this patent UNITED STATES PATENTS Number 

